diff --git a/webapprt/WebappsHandler.jsm b/webapprt/WebappsHandler.jsm
index 532a48669898..b4b8ec0d25d1 100644
--- a/webapprt/WebappsHandler.jsm
+++ b/webapprt/WebappsHandler.jsm
@@ -28,7 +28,7 @@ this.WebappsHandler = {
 
     switch (topic) {
       case "webapps-ask-install":
-        let chromeWin = Services.wm.getOuterWindowById(data.oid);
+        let chromeWin = Services.wm.getOuterWindowWithId(data.oid);
         if (chromeWin)
           this.doInstall(data, chromeWin);
         break;